The present invention relates generally to glands and more particularly to a split gland which can be laterally installed over a tube instead of having to be slipped over the end thereof.
Glands find significant and varied use in industry. For example, gland applications include attaching pneumatic and hydraulic lines in automotive, marine and aircraft systems and the like. Conventional threaded glands must be slipped over the ends of the tubing employed. The tubing is then usually either flared or ferrules disposed thereon near the end thereof, and the threaded gland utilized to secure the tubing to appropriate fittings having matching threads, forming thereby fluid-tight connections.
The tubing is generally preformed or bent to form. Once the tubing is bent a sufficient amount, conventional glands cannot slide over the bend because the inside diameter of the gland must be sufficiently small to hold the tubing in position when the gland is threaded into a fitting. Therefore, conventional glands can only be slid along straight tubing to tubing having gentle bends.
Additionally, the threads of a gland are occasionally stripped during the connection process of the tubing to a fitting, the flats of the gland head become rounded, or the gland may be discovered to be defective after it is in place on the tubing and the tubing flared or the ferrule mounted thereby preventing its direct removal. In these situations, the tubing must be cut in order that a conventional gland be removed. Significant effort may be required to replace or reconnect the severed tubing, especially in the situation where the tubing is formed having a series of tight bends and/or the tubing assembly is positioned in a difficult-to-reach location. For these and other reasons known to those skilled in the art of fluid actuated machinery, for example, it is desirable to have a gland which can be laterally slipped over tubing.
Two references are known to the inventor which are relevant to the subject invention. First, U.S. Pat. No. 4,343,496, "Split Gland," issued to Joseph J. Petranto on Aug. 10, 1982, describes a split gland similar in outward appearance to that for the subject invention. The gland disclosed in the patent requires a U-shaped retainer to align the two, substantially mirror-image half glands. This retainer is positioned relative to the other parts of the gland by slots in the half glands, necessitating additional machining steps in the manufacture of the gland, and more complicated assembly and use thereof. It was originally believed by the inventor that a four piece split gland would be required to stabilize the assembled gland in order to enable it to be threaded into a female fitting without cross-threading occurring. The alternative was to employ a very stiff and bulky spring clamp which would render the gland difficult to use for its intended purpose. Subsequent to the filing of the first split gland patent, it was discovered that the embodiments of the present invention described hereinbelow provide the required rigidity of location of the two halves of the split gland without having to resort to an oversized or overstiff spring clamp. A second reference, "Scanning for Ideas," Machine Design, Aug. 11, 1983, page 44, briefly describes a snap-on fitting derived from the invention disclosed in the above-mentioned patent. Although the description states that the two gland halves are notched for alignment and held together by a flat metal spring, there is no disclosed manner in which the two notched surfaces might engage in any way in order to provide some locking or alignment capability. Another piece, which inserts into the notches, must be provided. Such a member is not disclosed in the description of the apparatus. From the sole notch shown in the cutaway representation of the split gland shown therein and the similarity to FIG. 4 of the Petranto patent, however, the missing member is most likely the retainer described in the patent.